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<H1>IBM Visualization Data Explorer Programmer&#39;s Reference</H1>
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<H2><A NAME="HDRSNCS" HREF="progu075.htm#PToC_165">16.5 Screen Class</A></H2>
<A NAME="IDX1249"></A>
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<P>
A Screen Object is an Object that maintains a size and alignment with
the screen (output image) independent of the camera view and
scaling transformations applied to it.
<P>
Three options are provided for the interpretation of translations
applied to a Screen Object.
First, a translation applied to the Screen Object may specify a new
position for the origin of the Screen Object in world space
(<TT><STRONG>SCREEN_WORLD</STRONG></TT>).
Second, a translation applied to the Screen Object may specify a new
location for the Screen Object in the image, measured in pixels,
where (0,0) refers to the lower-left corner of the image
(<TT><STRONG>SCREEN_PIXEL</STRONG></TT>).
Third, a translation applied to the Screen Object may specify a new
location for the Screen Object in the image, measured in
viewport-relative coordinates, where (0,0) refers to
the lower-left corner of the image and (1,1)
refers to the upper-right corner of the
image (<TT><STRONG>SCREEN_VIEWPORT</STRONG></TT>).
<P>
In addition, with regard to <I>z</I>, the object may be displayed
either in place in the scene, in front of all objects, or behind
all objects, according to whether the <TT><STRONG>z</STRONG></TT>
parameter to <TT><STRONG>DXNewScreen()</STRONG></TT> is 0,
<I>+1</I>, or <I>-1</I> respectively.
<PRE><STRONG>
#define SCREEN_WORLD 0
#define SCREEN_VIEWPORT 1
#define SCREEN_PIXEL 2
</STRONG>
</PRE>
<TABLE CELLPADDING="3">
<TR VALIGN="TOP"><TD><P><B><TT><STRONG>Screen DXNewScreen()</STRONG></TT>
</B></TD><TD><P>Creates a new Object aligned to the final screen.
<A NAME="IDX1252"></A>
<A NAME="IDX1253"></A>
See  <A HREF="progu260.htm#HDRDXNSN">DXNewScreen</A>.
</TD></TR><TR VALIGN="TOP"><TD><P><B><TT><STRONG>Screen
DXGetScreenInfo()</STRONG></TT>
</B></TD><TD><P>Returns information about a Screen Object.
<A NAME="IDX1254"></A>
<A NAME="IDX1255"></A>
See  <A HREF="progu200.htm#HDRDXGSI">DXGetScreenInfo</A>.
</TD></TR><TR VALIGN="TOP"><TD><P><B><TT><STRONG>Screen
DXSetScreenObject()</STRONG></TT>
</B></TD><TD><P>Sets the Object to which a screen transform is to be applied.
<A NAME="IDX1256"></A>
<A NAME="IDX1257"></A>
See  <A HREF="progu325.htm#HDRDXSSO">DXSetScreenObject</A>.
</TD></TR></TABLE>
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